Here is a snapshot of developments in Ukraine since a political crisis erupted at the end of 2013:

November 2013

November 21: Ukrainian authorities suspend talks on an Association Agreement with the European Union in favour of closer economic relations with Russia, prompting pro-European opposition groups to call for protests.

December

December 1: After a week of smaller demonstrations, a crowd of up to 500,000 gathers on Independence Square in Kiev, setting up camp and building barricades.

December 11: Security forces move against protesters on Independence Square, but are forced back.

December 17: President Viktor Yanukovych travels to Moscow, where he secures a $17 billion bailout deal and a huge price cut for Russian gas.

February 5-6: EU foreign policy chief Catherine Ashton and the top US envoy to Europe, Victoria Nuland, visit Kiev.

February 7: Mr Yanukovych meets his ally, Russian president Vladimir Putin, on the sidelines of the opening ceremony of the Winter Olympic Games in Sochi.

February 9: Some 70,000 protesters gather on Independence Square.

February 10: The EU stops short of any immediate threat of sanctions.

February 14: All 234 protesters who have been arrested since December are released but charges against them remain.

February 16: Protesters evacuate Kiev city hall after occupying the building since December 1, along with other public buildings in the regions. A day later arrested protesters are granted amnesty.

February 17: Moscow says it will release "this week" $2 billion from a vital aid package to Ukraine.

February 18: At least 26 people, including 10 policeman, are killed in the bloodiest day of clashes in nearly three months of protests. Protesters take back control of Kiev's city hall. Riot police encircle Independence Square, where some 25,000 protesters remain after the expiry of a ultimatum from security forces demanding calm be restored.

February 19: President Viktor Yanukovych agrees to a "truce" with opposition leaders and a start to negotiations to prevent further bloodshed. Opposition leader Arseny Yatseniuk announces that a planned raid of Independence Square will not take place. EU leaders call an emergency meeting expected to consider laying sanctions.

February 20: - Demonstrators charge a police line in Kiev, shattering a truce called by Mr Yanukovych less than a day earlier. At least 25 protesters are killed, according to AFP correspondents. The interior ministry says two police officers were shot dead.

February 21: Mr Yanukovych and opposition leaders sign a deal aimed at ending the bloodshed. The deal calls for presidential elections by December, the formation of a national unity government and constitutional changes to reduce the president's powers.

February 24: Ukraine issues an arrest warrant for Mr Yanukovych and launches a probe into the "mass murder" of protestors in Kiev.

February 26: Russian president Vladimir Putin orders an urgent drill to test the combat readiness of the nation's armed forces in the western Russia. This includes army, navy and air force troops. Moscow grants Mr Yanukovych refuge.

February 27: Pro-Russian fighters storm government buildings in the Ukrainian region of Crimea.

February 28: Armed men seize the Simferopol International Airport and a military airport in Sevastopol, Crimea.

March

March 1: Mr Putin asks the Russian parliament to approve the use of military force in Ukraine, which the parliament grants. US president Barack Obama warns Russia "there will be costs" for any military intervention in Ukraine.

March 2: Ukraine's navy chief Denis Berezovsky defects, swearing allegiance to Crimea in the presence of the region's unrecognised pro-Russian leader and surrendering his headquarters at the port of Sevastopol, as Russian forces consolidate their hold on the Black Sea peninsula.

March 3:Russia's ambassador to Australia emerges from an official call-up to the Foreign Affairs Department in Canberra, warning that his country will act to "ensure the interests" of Russians in Ukraine.

March 4: Mr Putin delivers a robust defence of Russia's actions in Crimea, saying he will use force in Ukraine only as a last resort. Mr Obama says Mr Putin is "not fooling anybody".

March 5: Russia successfully test fires an advanced ballistic missile. It is reported former prime minister Kevin Rudd is in Russia and will be heading to Ukraine as part of a visit booked "more than a month ago", according to his spokeswoman.

March 6: A United Nations diplomat sent to Crimea was forced to abandon his mission after he was threatened by pro-Russian gunmen and later heckled by protesters.

March 7: The parliament in the Ukraine region of Crimea votes to become part of Russia.

March 8: Russia warns the United States against taking "hasty and reckless" steps over Moscow's military intervention in Crimea.

March 11: Armed men seize a military hospital and a missile base in the Ukrainian region.

March 14: German chancellor Angela Merkel says Russia risks "massive" political and economic damage, if it continues to destabilise the situation in Ukraine.

March 15: Russian foreign minister Sergei Lavrov and US secretary of state John Kerry fail to reach an agreement to ease the crisis.

March 16: Russia vetos a UN Security Council draft resolution that declared a planned referendum on the status of Ukraine's Crimea region invalid as Crimeans vote in referendum to decide whether the Black Sea peninsula leaves Ukraine and becomes part of Russia.

April 18: Ukrainian, Russian and Western diplomats agree on "initial concrete steps" to help resolve the confrontation, but Mr Obama says there is no guarantee it will be successful in de-escalating the conflict.

April 24: A local politician is found dead in the country's east, prompting calls from Mr Turchynov for renewed anti-terrorist action against pro-Russian militants.

April 29: Separatists claim the town of Kostyantynivka as the US announces fresh sanctions on seven Russian officials and 17 firms linked to Mr Putin's inner circle.

April 30: Hundreds of pro-Russian separatists storm government buildings and open fire on police in Luhansk.

May

May 1: Mr Turchynov issues a decree to reintroduce military conscription in Ukraine with immediate effect.

May 3: A building fire kills at least 30 people while three others are shot dead during street battles in Odessa.

May 5: More than 1,000 pro-Russian militants free 67 of their comrades after surrounding an Odessa police station.

July 6: Pro-Russia fighters abandon their main stronghold of Slaviansk in eastern Ukraine after government forces launched an offensive on the city.

July 14: Ukrainian forces launch major offensive against pro-Russian rebels in the country's east, with army units launching an assault on the regional capital Luhansk.

July 17: US imposes further sanctions on Russia's economy, including Gazprombank and Rosneft Oil Co, and other major banks and and energy and defence companies.

July 18: Russian jets shoot down a Ukrainian SU-25 fighter plane that was on military operations over the east of Ukraine.

July 18: A Malaysia Airlines passenger jet crashes in Ukraine near the country's border with Russia, killing all 298 people on board. Ukraine's government says it is possible the airliner was shot down by a ground-to-air missile.

July 19: Gunmen prevent international investigators from securing MH17 crash site. Fighting between Ukraine forces and pro-Russian separatists continues around the disaster zone.

July 19: Foreign Affairs Minister Julie Bishop heads to New York to campaign at the United Nations for an international investigation into those responsible for downing MH17 and to push for access to the crash site.

July 22: UN Security Council unanimously backs an Australian-sponsored resolution over the downing of MH17 which calls for an international investigation.

July 25: Ukraine's prime minister Arseny Yatseniuk quits on the same day two parties quit the government coalition, forcing new elections for a parliament which has not changed since before the toppling of Mr Yanukovych in February.

July 27: International investigation team forced to delay their planned visit to the MH17 crash site after the area was declared unsafe because of nearby fighting.

July 30: The European Union and the United States impose tougher sanctions against Russia in an attempt to prevent further destabilisation of Ukraine.

July 30: Intense fighting between government troops and pro-Russian rebels kill dozens of civilians, soldiers and rebels, as Kiev pressed on with an offensive to defeat the Moscow-backed revolt.

August

August 5: President Petro Poroshenko says government forces have retaken three-quarters of rebel territory in two months.

August 7: Russia retaliates against the new Western sanctions, banning most food imports from the US and the EU.

August 11-14: Ukraine's military says it is close to completely surrounding rebel forces in Donetsk and Lugansk, cutting off roads between the two cities.

August 15: Ukraine says it has destroyed part of a Russian military convoy that crossed into its territory.

August 18: Kiev accuses rebels of firing on refugees near Lugansk; 17 bodies are found the next day.

August 25: Rebels mount a counter-offensive in the south-east. Kiev says it has stopped an armoured column coming from Russia near the coastal town of Novoazovsk, and captured 10 Russian paratroopers. Moscow says they crossed the border "by accident".

August 26: Mr Poroshenko and Russian leader Vladimir Putin meet in Minsk on the sidelines of an EU summit, without results.

August 28: Kiev says Russian troops have seized the border town of Novoazovsk, accuses Moscow of a "direct invasion" and calls for EU military aid. Mr Poroshenko scraps a visit to Turkey as NATO releases satellite imagery which it says proves that more than 1,000 Russian troops are in Ukraine. The US ambassador accuses Russia in a Twitter message of direct involvement in the fighting, but Moscow denies that any Russian soldiers are in eastern Ukraine.

August 29: NATO tells Russia to stop its "illegal military actions" in Ukraine at emergency talks on the crisis. Mr Putin calls for the Ukraine government to hold "substantial" talks with the rebels, while hailing the separatist fighters as defenders of "Novorossiya".

August 30: Mr Putin calls for the first time for "statehood" status for the east of Ukraine.

September

September 1: Ukrainian forces withdraw from Lugansk airport, followed by other pullouts from around rebel-held areas. Kiev accuses Moscow of launching a "great war" that could claim tens of thousands of lives.

September 3: Mr Putin unveils a seven-point peace plan for Ukraine after talks with Mr Poroshenko.

September 4: NATO hosts summit devoted largely to Ukraine.

September 5: After almost five months of fighting, rival parties sign a 12-point ceasefire in Minsk that takes effect at 1500 GMT. NATO leaders agree to set up a rapid reaction force, and the EU agrees on new economic sanctions on Russia.

September 6: Russia warns it will respond to any new sanctions. Eastern Ukraine remains calm overall although rival sides accuse the other of ceasefire violations.

September 7: In Mariupol, a 33-year-old woman is killed – the first civilian casualty in a two-day-old ceasefire – while Ukrainian government forces and pro-Russian separatists say the ceasefire is still holding.

September 8: Russia threatens to retaliate against western sanctions, by blocking flights through its airspace.

September 9: Dutch investigators release a report saying MH17 was brought down by "a large number of high-energy objects", with no technical faults or pilot error found.

September 12: Ukrainian president Petro Poroshenko hopes to secure "special status" with the United States as he prepares to travel to the White House, further signalling Kiev's move away from Russia's orbit. Investigators find 25 pieces of metal in baggage and bodies of MH17 victims, which could reveal type of missile used to down the aircraft in July.

September 13: United States steps up sanctions against Russia, including against Russia's largest bank, and bars suppliers from dealing with five Russian energy companies.

September 16: Ukraine's president offers parts of the rebel-held east three years of limited self-rule in peace deal.

September 17: Russia threatens to send more troops to Crimea, after NATO begins exercises in western Ukraine.

September 19: US president Barack Obama welcomes Ukrainian president Petro Poroshenko at the White House, and pledges $US50 million in military aid but no weapons.

September 20: US and Canadian warplanes intercept Russian fighter jets, refuelling tankers, and long-range fighter jets in airspace off Alaska.

September 21: Ukrainian government negotiators and pro-Russian rebels agree on a nine-point peace plan to reinforce the current shaky ceasefire in eastern Ukraine, while NATO warns the plan is "in name only".

September 22: Tens of thousands of protestors march in Moscow to protest against Russia's involvement in the Ukraine conflict.

September 29: Ceasefire shows strain as seven Ukrainian soldiers are killed in separatist shelling near Donetsk in the eastern part of the country.

October

October 1: Pro-Moscow MP Nestor Shufrich is beaten by a mod during election campaigning in Odessa, while ten people are killed in shelling at a school in Donetsk.

October 4: Twelve pro-Russian separatists are killed in attacks at Donetsk airport, the biggest loss of life since the ceasefire began one month ago.

October 10: Dutch foreign minister Frans Timmermans reveals on a Dutch chat show that one of the victims of the MH17 crash was wearing an oxygen mask, raising the possibility that some passengers may have been conscious when the aircraft went down in eastern Ukraine.

October 13: Russia's president Vladimir Putin orders 17,000 troops to withdraw from the Ukrainian border and return to their bases, after finishing a training exercise in the Rostov region. Australia's Prime Minister Tony Abbott says he plans to "shirtfront" Russian president Vladimir Putin at the G20 Leaders' Summit in Brisbane in November.

October 14: A small team of Dutch investigators returns to the MH17 crash site, and carries away boxes of possessions – including cuddly toys – as fighting continues nearby.

October 17: Ukrainian, Russian and European leaders meet in Milan, Italy, to discuss the crisis.

October 18: Australia's foreign minister Julie Bishop has a "detailed 25-minute discussion" with Russian president Vladimir Putin to request investigators be given further access to the MH17 crash site.

October 26: Ukraine holds parliamentary elections with president Poroshenko, who was elected in May, calling for a break from past ties with Russia.

October 28: Russia says it will recognise the results of the parliamentary elections, even though elections are not held in rebel-held regions.

November

November 2: Pro-Russian rebel leader Alexander Zakharchenko wins "illegal" elections in eastern Ukraine as a show of defiance against the government. The West denounces the poll.

November 5: Ukrainian president Petro Poroshenko orders new military units to protect several towns in the south and east of the country from possible attack by Russian-backed militants.

November 5: Two teenagers are killed as shelling hits a school sports ground in the eastern rebel-held city of Donetsk. The shelling occurs 2 to 3 kilometres from Donetsk airport, which separatists have been trying to seize from government forces despite a two-month-old ceasefire.

November 13: A senior UN official warns open warfare may erupt once more in eastern Ukraine, with reports of Russian tanks and troops crossing the border. More than 930,000 people have been driven from their homes since the conflict began.

November 15: Ukraine's prime minister Arseny Yatseniuk says the top priority for his new government is to build an army strong enough to stop Russian military aggression, as he holds power-sharing talks with president Petro Poroshenko and others to form a coalition government following the October elections.

November 16: Five civilians, including two children and three government soldiers, are killed in fighting in eastern Ukraine, prompting German chancellor Angela Merkel to consider harsher sanctions against Russia.

November 16: At the G20 Leaders' Summit in Brisbane, Russian president Vladimir Putin says there is a "good chance of resolution" in Ukraine, while Canadian prime minister Stephen Harper agrees to shake Mr Putin's hand but tells him to get out of Ukraine. Work begins to remove MH17 wreckage from rebel-held territory in eastern Ukraine, four months after the aircraft was shot down killing all 298 people onboard.

November 17: Ukrainian president Petro Poroshenko says his country is "prepared for total war" as fighting continues around the pro-Russian rebel stronghold of Donetsk, while Russia plans its own version of Wikipedia to ensure "detailed and reliable" information about Ukraine.

The United Nations says more than 4,000 people – most of them civilians – have died in the conflict since April.